After using the two major moves of the Eight Desolate Refining Hell Halberd, an instantaneous burst of battle strength could reach the late period of the Fifth Layer Heaven, and activating the Elephant's Fury Rune burst could sweep across the Fifth Layer Heaven.
Comparing the two, it seems that Jack's normal battle strength was only two minor realms higher than Christopher's.
But one must know that the other party's cultivation was at the late stage of the Fourth Layer Heaven, and their True Strength was several times richer and more solid compared to Jack's at the early stage of the Fourth Layer Heaven.
In the earlier battle, Jack's True Strength was almost exhausted, and he was completely relying on his absolute physical strength to press down on his opponent.
Moreover, he had to wrap the remaining True Strength around the war halberd to prevent it, a mere alloy weapon, from being damaged or even broken by the opponent's transcendent combat knife.